The Paradigm Shift Predicament
by Penny Parsons
Summary: A shift in one relationship affects another. Vague yes but I'm no good at these things. Rated T for things to come. This story could turn in to a long one so stay tuned....
1. Chapter 1

The Paradigm Shift Predicament

By Penny Parsons 

**Author's Note: **I do not own The Big Bang Theory or anything associated with it. I do however own this here little story.

****

Chapter 1

"What?!" Penny exclaimed, feeling numb. Deep humiliation was starting to lump in the bottom of her stomach.

"Penny, I'm so sorry. I never meant for this to happen." Leonard tried to explain himself but nothing he could say could justify what he had done.

"You slept with your coworker, Leonard. I mean, I know that Katherine is attractive and intelligent and everything but we've been dating for almost a year!" Penny's voice was rising but wavering. She would cry if she wasn't so damned angry.

Leonard's face held an immense amount of guilt. He breathed a deep, heavy sigh. "Penny I care so much about you but lately we've been fighting and with this new experiment that I've been working on, we barely get to see one another."

"So instead of telling me this, you decide to bang your little lab partner and then still sleep with me whenever you had the time. You know, I can't believe you. You pined after me for two years and then when I give you a chance and start to think that I loved you, you go and bang the next hot girl that comes along." Penny shook her head in amazement. As her anger rose she stood up from the maroon leather couch. "And another thing, I can't believe _you_ were the one who cheated on _me_! I mean, look at _you _and look at _me_. I just-I just can't believe this!"

"Hey now, that's not fair! I'm not some hideous monster and you're not some perfect princess. Penny I'm sorry. This was the last thing that I wanted to do to you. I didn't want it to end like this!" Leonard said becoming defensive which meant his voice was whinier than ever.

"You know, I thought you would be different Leonard. I guess I really am just another dumb blond. Leonard Hofstadter, you are low. You are nothing but a two timing, little creep. I never want to see your face or hear your whiny voice ever again!" Penny screamed, marching out of apartment 4A, slamming the door behind her.

Sheldon, Raj and Howard had just made it to the top step of the fourth floor landing when they heard the commotion and watched an enraged Penny march to her own apartment.

They looked at each other and shrugged, simply assuming it was yet another lover's spat of Leonard and Penny.

But when they walked through the front door and spotted a beaten down and miserable Leonard they knew this had not been your everyday spat.

Howard, having Bernadette to only dump him two months prior, knew the tell tale sign of a broken hearted man. "Is everything okay, Leonard?" Howard asked, obviously concerned.

Leonard heaved another heavy sigh. "No Howard everything isn't okay. Penny and I just broke up-for good this time."

"Well I'm not surprised Leonard. Even though this little tryst lasted longer than what I had hypothesized I knew eventually Penny would tire of coitus with you and go back to her own kind." Sheldon smugly interjected.

"Penny didn't break up with me." Leonard stated quietly.

"Come again?" Howard asked with raised eyebrows.

"Oh man. Do you know Dr. Katherine Parks?" Leonard asked.

"Yes." All three men answered in unison.

"Well we've been having sex for the last month or so and I told Penny today. Of course I don't think our relationship would recover from my little confession anyway and there is a huge possibility that I may be in love with Katherine." Leonard didn't look up from his hands as he spoke but when he did he was met with three very stunned friends.

Raj was the first to speak. "Dude, are you crazy! Penny actually gave you a chance and this is how you repay her? By sleeping with the second hot girl to come along and pay attention to you. That is low."

"Yea Leonard, people expect this from me but not from you." added Howard.

"Look, I'm human too! I made a mistake and I handled it badly." Leonard admitted, "And as for you Raj, just because Penny graced me with her presence doesn't mean that I was to spend our entire relationship groveling at her feet?"

Silence hung in the air for a few minutes. Howard, shaking his head said, "I don't know man. This was just a low blow from you. I'm surprised and shocked. I know Penny wouldn't want any visitors right now so I'm just going to head home. I'm sorry Leonard but I can't look at you right now."

Raj followed Howard out only stopping for a second to shake his head at Leonard.

When the door closed behind them, Leonard turned his attention to the unusually quiet Sheldon. "Well any quips or ridicule?"

Sheldon's blue eyes moved fervently across the floor, trying to process what had just happened. "Leonard how could you do this to Penny?" Sheldon asked his voice coming out small and sad.

"Now don't tell me that you're going to take Penny's side too? I mean, yes what I did was terrible, but I didn't mean for all this to happen." Leonard said defending himself for the third time within an hour.

"Well, what did you mean to happen? I don't understand it."

"I meant to stay with Penny, love her, marry her and live happily ever after. But after meeting Katherine I realized Penny wasn't the one for me and I fell in love with Katherine instead." Leonard paused before adding, "And besides Sheldon, what would you know about love and sex and relationships for that matter. You said so yourself that you don't understand."

Sheldon was pensive for a moment. "True, I've had no desire for a romantic, sexual relationship but I have pursued and maintained four friendships. While natural monogamy among our species is a debatable topic I know that when you care about someone you should inform them that you want to engage in sexual intercourse with another mate or what my mother would call, common decency."

"Common decency? You want to talk to _me_ about common decency? That is really rich Sheldon. When have you ever had common decency towards another human being?" Leonard asked in a huff.

"While others may perceive me as "difficult", I have gone out of my way on several occasions to accommodate another person's needs." Sheldon stated.

"Name one?" challenged Leonard.

"Alright." Sheldon said clasping his hands behind his back. "I have lent money. I have helped people advance to other levels on Conan the Barbarian. I have helped people start and maintain a small business. I have given gifts not to mention hugs. I have driven people to the hospital and then back to their place and put them to bed. I have given countless advice when asked and kept many secrets. Leonard I could go on and on but really what's the point?"

"Sheldon?"

"What Leonard?"

"You do know that when you say "people", you mean Penny."

"What? No-I-"

"Yea, Sheldon you've done most if not all those things only for Penny."

"Well there you go. Maybe I'm not as yielding to my male friends but when it comes to my female friends, or should I say female friend, I do in fact have the common decency to treat them a little better than you."

"Whatever Sheldon. I need to go lie down and I can't listen to anymore of this lecture, let along from you. Please don't talk to me for the next couple of days; it's going to be rough as it is." Leonard mumbled as he went inside his bedroom.

Sheldon stared after his roommate as he settled in to his spot, contemplating the immense paradigm shift that was taking place. It was true that Sheldon had never been in favor of Penny and Leonard dating but he was certain she would have ended it. He was surprised at Leonard, so surprised that it made a heavy feeling form in the pit of his stomach and spread throughout his chest. Sheldon was sad. His sadness was intensified when his mind would shift to Penny. How was she doing? How was she feeling? Is she going to be okay? Would she still join them for Thai take out and Halo night?

Of course, Sheldon rarely cared how people "felt" or how they were doing. But this situation called for a little more reflection than usual. Truer still was that Penny somehow always managed to get under his skin. They were constantly sparring and as hard as this was to admit, she had bested him on more than one occasion. Despite all their differences and fighting, Sheldon cared for Penny or at least found her tolerable. She kept him on his toes and had taught him more about social conventions and obligations since he had left his mother and meemaw behind in Texas. Heck she had maybe taught him more in the past 3 years than he had learned in his whole life. And now thinking of her probably crying and devastated in her messy apartment prompted him to walk over to 4B and see how she was doing.

Knock, Knock, Knock. "Penny."

Knock, Knock, Knock. "Penny."

Knock, Knock, Knock. "Penny."

"Go away Sheldon, I'm not in the mood!"

"But Penny I would like to speak with you."

"Look!" She said as she opened the door, "I am in no mood to hear you gloat and say I told you so!" Penny's face was red and puffy and her hair was in a messy bun atop her head.

Sheldon studied her for a moment and she thought she recognized sadness and possibly empathy in his blue eyes.

"May I come in?" He asked earnestly.

Penny sighed, "Sure come on in." She stepped aside to let the tall physicist walk in.

As soon as she closed the door behind them, Sheldon spun around and embraced her in hug.


	2. Chapter 2

**Author's Note: **I do not own The Big Bang Theory or anything associated with it. I do however own this here little story.

____________________________________________________________________________________________________________________

Sheldon's hug was tight, almost suffocating as if he was afraid to let go. Sheldon had hugged her on more than one occasion but something about this hug was different. It was not awkward or stiff. It was…well…_warm_.

"Penny, I am so sorry." Sheldon whispered against her blond hair.

"Sweetie, how many times do I have to tell you? You don't have to apologize for showing affection."

Sheldon pulled away still holding her at arm's length and studying her face. "No not that, I'm sorry about you and Leonard."

Penny's face instantly darkened. "Oh you heard about that already."

"Well Raj, Howard and I entered the apartment only seconds after you had left. We could tell something was afoot." Sheldon explained, his voice soft, almost human like.

Penny chuckled to herself despite being broken hearted.

"What is so funny? Have you gone insane from experiencing a traumatic event?" Sheldon asked with one cocked eyebrow.

Penny sighed. "No Sheldon, I believe I am perfectly sane. I forget sometimes that you're human and not some robot sent here to observe the behavior of Earthlings."

Sheldon seemed a little miffed at the comment and Penny instantly felt bad. "I'm sorry Sheldon that was rude. I appreciate you coming over here and comforting me."

"You are most welcome Penny. As you know I do not have the experience nor the interest in so called romantic relationships but I do know that infidelity is looked down up on in our society." He stared intensely into her eyes, making her feel a little uncomfortable.

"Yea it's a real bummer." Penny said plopping down on her turquoise couch.

Sheldon followed, tossing a few articles of clothing out of the way before sitting down. "Penny, why haven't you kept up with the organizational plan I left for you?"

Penny shot Sheldon one of her infamous death glares.

"I'm sorry Penny this may not be the appropriate time to point out your flaws." Sheldon quickly said apologizing yet not.

"Are we done here?" Penny asked becoming more irritated by the minute.

Sheldon looked confused, "What exactly am I suppose to be 'done with'?"

"I don't know. Whatever you came over here to do, are you done yet?" Penny asked again, exasperated.

"Well I came to express my sadness over Leonard's utter disregard to social conventions." Sheldon stated as Penny's shoulders seem to sag. "Did I say something inappropriate?" Sheldon asked noticing Penny's slight change in demeanor.

"Not exactly…I'm just completely and utterly devastated. Leonard was the last person that I thought would cheat on me. I mean, why does this keep happening to me? Am I some horrible person that Karma keeps screwing me over with lying, cheating boyfriends? And to hear you treat our relationship like some general 'social convention' doesn't help either!" Penny wiped a few tears from her cheeks not realizing when she had started crying. Maybe she had never really stopped.

"First off, the notion of Karma does not exist and second my intention wasn't to make you feel worse. I don't know why you've had a succession of men cheat on you; I don't think there's an equation to answer that. But-"

"Oh my God Sheldon! What the hell? Don't you understand that the one man who I thought would be different and actually love me, slept with another woman? Leonard betrayed me! And here you are claiming that you were concerned about me but the whole time you've been rambling on and on, making me feel worse! I hate how you always find a way to make me feel stupid! I know I'm stupid, okay! Just get out and don't talk to me." Penny could feel heat rising to her face and her breathing was becoming a little erratic.

Sheldon looking alarmed, shot up out of his seat. "Penny I hugged you! How is that not seen as helping? For the record Penny, you are not stupid. Yes you may have a lower IQ than myself and the others and yes you do not understand anything about mathematics or physics or…"

"Get out! Get out, get out, get out!" screamed Penny interrupting Sheldon before he dug himself further in to one of his holes.

"Fine, I can see that you are clearly emotionally distressed. If you are not going to let me finish then I'll 'get out' as you so kindly put it." Sheldon turned to exit but paused with his hand on the doorknob and his back to Penny.

"Penny you're not stupid. You're a very smart woman. You are aware of things that none of us in our circle of friends see or understand. You are more than capable of learning and doing more." Penny stared at Sheldon's back, stunned.

"And Penny-" Sheldon added as he turned around to look at her, "I am sorry that Leonard did this to you. I'm sorry that you're hurt and sad." His blue eyes rested gently on her green ones for a moment before closing the door behind him.

Penny stood there, momentarily stunned. She heard the door across the hall close. Sheldon actually said something really sweet to her. If Leonard had not been home, Penny would have run next door to return the hug.


	3. Chapter 3

It had been three weeks since Leonard and Penny had broken up.

Leonard and Katherine were pursuing a relationship. Penny avoided Leonard at all cost and Sheldon visited Penny's apartment once a day.

Monday through Friday he would go over right after work and left her food, a note for instructions to eat and then tidy up. Sometimes she would be there.

Since she was a waitress of course, she did not have a set schedule. Also, Penny had picked up as many shifts as she could to keep her mind off things. Sheldon liked when Penny was present though, that way he could physically see her eat, even if it was only a couple of bites.

Sheldon began to suspect Penny would go a whole day without eating. He noticed that she was losing weight quickly. Some mornings he would find her portion of take-out still sitting in its container, untouched and with disgust he would have to throw it all away.

He began to suspect she wasn't sleeping either. Dark circles were appearing under her eyes.

He noticed sometimes too in those first two weeks that during her days off or after work, she was drunk. This was not a laughing, bubbly drunk it was a dark and depressing drunk. But Penny gave up on drowning her sorrows with alcohol since the hangovers weren't helping matters.

The first two weeks Penny was also very clingy. When they were together in her apartment she would throw her arms around his waist and hide her face in his shirt. Of course this made Sheldon uncomfortable, what with human contact and all. But looking at her and looking at how she clung to him, she reminded him of a little child, a helpless baby that he had to take care of.

Of course he didn't _have_ to take care of her. Yet Sheldon saw this as a non optional social convention and really, if he didn't take care of her no one else was going to.

Howard and Raj tried to ignore the situation as much as possible. They came over for a couple of visits but were obviously uncomfortable especially when Penny would start crying out of nowhere. Also it didn't seem like Penny had any close female friends or any other friends at that.

Sheldon felt like this was his obligation because in the past four years this was how their friendship worked. They would bicker and get on one another's nerves but every time one of them was in need it was always the other that was there to help.

Sheldon sighed, deep in thought and poking his food with his fork.

"You alright there buddy?" Howard asked looking up from his tray of food.

The school cafeteria was noisy as ever but Sheldon felt as if he was a million miles away.

"Yes I am fine, I'm a little worried about Penny though." He said.

"I know, we all are." Howard offered.

Sheldon gave him a blank stare. "Are you implying that you and Raj are worried about Penny? If that is correct then why have I been the only one taking care of her?"

"Dude we know and we feel bad for not being there more, but we don't know what to do." Raj interjected.

"Yea for some odd, inexplicable reason you know how to take care of a person." Howard said.

"Penny is my friend. She's sad and she's been through a traumatic event. I go over to her apartment. I sit with her and watch TV and I sit there while she cries. I make sure she eats something. I ask her every now and then how she is even though I know she'll say 'fine' and even though I know she's lying. I'm there because I feel like I have to be. It's not a big deal and it is not that hard to do." Sheldon looked back at his uneaten food.

Howard was about to say something else when Leonard and Katherine plopped down at their table.

"Hey guys, what's up?" Leonard asked opening his water bottle.

Katherine offered up a shy glance and a half smile. It was obvious she felt uncomfortable around the group knowing that they were well aware of what happened.

Raj shrugged his shoulders and Howard mumbled a 'not much'. Sheldon continued to poke at his food. Leonard and Katherine exchanged glances.

Leonard cleared his throat. "Um, I was thinking of having Katherine over for Halo night. Let you all get to know her outside of work."

The other three guys looked at one another. Raj and Howard nodded their heads and managed a weak smile.

"I do not like that idea, Leonard." Sheldon said staring hard at his roommate.

Leonard shared another look with his new girlfriend. "Sheldon I know this may seem weird at first, but Katherine is my girlfriend now and I want her to feel like she can come to my apartment, get to know my friends and feel comfortable in doing so."

"Leonard, you committed infidelity. You were copulating with another woman for an entire month while still copulating with Penny. May I remind you that this same Penny was your girlfriend for over a year. This same Penny was a woman you chased after for two years. Now this same Penny has been devastated by you and I have to go over there every day just to make sure that she eats and you want to bring Katherine over for Halo night like none of that took place?" Sheldon stared at Leonard expecting an answer. Leonard hung his head in response.

Katherine gathered her courage and spoke, "Sheldon I know that the way Leonard and I handled things were wrong. We let things get out of hand and I feel terrible for what we did to Penny. I have never met her but I've heard wonderful things about her, which makes this all the more agonizing. I'm not asking you or anyone to like me right now but I do love Leonard, I can't help that and I'm just asking all of you to give me a chance."

Sheldon's shoulders sagged under her sincerity. "Fine, come over to Halo night. But remember it may take me a long time, if ever, to even consider you an acquaintance."

"Fair enough." Katherine attempted a weak smile, knowing this was the only thing she could ask for.


	4. Chapter 4

**Author's Note:** Sadly I do not own TBBT. If I did, this story would not be merely fanfiction but a script of a broadcasted episode. Thanks to everyone who has read and reviewed my story. The comments are much appreciated!

At times the pain was almost unbearable. Penny didn't know how much time had passed. Days, weeks, hell it could have possibly been months.

It took all her strength to crawl out of bed in the mornings; on her days off she would literally sleep all day. Work was routine and she pretended she was a robot programmed to do her duties then shut down afterwards.

Sometimes it would be three days or longer before she would shower. Sheldon would let himself in almost everyday to check on her. He tried to get her to play Halo with him and the guys when Leonard was not there. He brought Penny her portion of take out. She would eat a bite or two then set it on her kitchen counter until he came the next day and threw it in the trash.

One evening (or was it morning?) Penny wasn't sure, Sheldon stood over her with his arms crossed in front of his chest. "Penny you need to eat something." He said sternly.

"I don't feel like it." She mumbled into her pillow.

Sheldon sighed and slowly sat down on her bed. "Penny you've always had a low body mass for your height, age and skeletal frame but I believe your body mass is much too low now. I know that some females want to look emaciated because of our modern Western concept of beauty but I have never found that look to be remotely attractive." Sheldon paused to sigh again. "Penny you look terrible. You need to eat."

Penny rolled over to look at him. Was he angry? He sounded a little angry. "Sheldon I just don't feel like eating. It takes all I can do to take a couple of bites and swallow without barfing all over the place."

Another sigh from Sheldon, except this was deeper and she could almost hear his teeth grinding together. "Get out of bed."

"I don't want to Sheldon. Leave me alone." Penny tried to roll back over but Sheldon grabbed her upper arm with his right hand, throwing the blanket off of her with the other.

"What the hell, Sheldon?" Penny was alarmed at his forcefulness.

"I said, get out of bed."

When Penny resisted, his grip became tighter and he literally yanked her out of bed dragging her to her feet. He pushed her to the bathroom and spun her around. Penny was face to face with her reflection. "Look at yourself Penny." Sheldon ordered.

Penny's green eyes widened as she stared at her reflection. It was as if it had been a lifetime ago since she had done so. Her hair was tangled and stringy. She had dark circles under her eyes and her cheeks were almost hollow. "Oh Jesus, I do look terrible."

Her gaze drifted to Sheldon's reflection as he stood behind her watching her with a 'no duh' expression on his face.

"Step on your bathroom scale Penny so I can determine your weight." Sheldon ordered again.

Penny nervously stepped on the scale and tears sprang to her eyes as the scale read 95 lbs.

"Oh God! I've lost 15 lbs in--!" She shrieked.

"Three weeks, Penny, it has been three weeks since you and Leonard broke up." said Sheldon shaking his head. "Penny, Penny, Penny, that is not a healthy amount of weight to lose for someone of your size and in such a short amount of time."

"I'm sorry Sheldon, I haven't had an appetite and I didn't realize how much time had passed."

"Penny I need you to take a hot shower and I'll make you some lunch, okay?" He spoke to her like she was a child. She thought it funny because it was usually the other way around.

She didn't mind being treated like a child, she felt like a child: vulnerable, sad and scared. She needed someone to take care of her and right now, Sheldon Cooper was the only one that was up for the task.

The smell of vegetable soup and biscuits wafted in to Penny's bedroom as she exited her bathroom. Her hair was wet and uncombed and she managed to wrap her bathrobe around her, following the scent of comfort food.

"Where did you find soup and bread?" Penny asked.

"Where do you think? I certainly did not find it in your pitiful empty cupboards. I remembered this in my kitchen. These food items seemed like a homey sort of meal that I thought you would appreciate at a time like this. It occurred to me that our usual take out fare may not have been best for you since you may have an emotional attachment and…memories to such cuisine. "

Penny managed a weak smile. "Sheldon?"

"Yes Penny?"

"Why are you doing this?"

Sheldon stopped in mid stir. "Well, Penny, you are my friend, you've been through a traumatic event, and no one else is looking after you. I felt that this is a non optional social convention and apart of our friendship agreement." He began to stir again, not missing a beat.

"Oh. Well thank you." Penny managed a half hearted smile.

Sheldon served Penny her meal, giving her large portions, obviously hinting that Penny needed to eat as much as possible. "Good lord Penny!" He cried out, "You are going to catch pneumonia!"

"What?" Penny said in between mouthfuls. Yes this was the kind of food she had needed.

"Your hair is soaking wet, you're barefoot, your skin is still damp and since your chest is not properly covered I can see most of your breasts!"

"What?!" She looked down realizing her bathrobe was not quite tied. Most of her chest and the start of her abdomen were exposed. "Oh geez Sheldon, I'm sorry, I guess I didn't tie my robe tight enough."

"Seriously Penny, do I have to do everything?" He left the kitchen with a tsk, tsk. He emerged moments later with a towel and a comb. "First let's dry that hair a little more and get that mess of tangles combed out."

Penny sat and ate her lunch while Sheldon did just that.

"Penny you have reverted back to being a little child. You are sparking some sort of paternal instinct in me, I don't like it!"

Penny laughed. She actually laughed for the first time in three weeks. "Is that what it's like to have a paternal figure take care of you? I can't imagine my dad taking care of me like this."

"Yes I agree. My father may have been similar to your father. He would have never enacted something of this nature either. I believe our fathers were shaped by some Western, rugged rural idea of men. While it is true that women give birth and nurse babies, in more primitive societies both genders usually had a hand in child rearing. It was not until our progress in to an industrialized society that men, having more physical strength moved away from the home to work in factories, thus leaving the mother at home to become it's center and equivalent."

"Too bad that many families can't go back to that way of life. Of the dad and the mom being able to show emotion and take care of the children together." Penny paused for a second before asking, "Sheldon, you've never really said much about your dad, why is that?"

Sheldon inhaled deeply. "I suppose it is because I don't want to talk about it." He said in his curt Sheldon-y way.

"Fair enough." Penny replied taking another big bite of soup and bread.

"Well look at you Penny. You've almost eaten the whole bowl! Good for you."

Penny had to laugh again. "Sheldon you really don't have to treat me like a baby. I'm fine."

"I guess I can't help myself. For whatever reason, you bring that out in me." Sheldon said as he finished combing out all her tangles. "Seriously Penny when was the last time you brushed your hair?"

"Geez, I don't even remember. That's a bad sign isn't it?" Sheldon agreed with a nod.

"Is your half nudity safely censored?"

"Oh yea, you can look at my face now without being distracted." Penny teased.

"I wasn't distracted per say, I have never been that exposed to your body. How was I not supposed to look?"

"Um, hello, remember when I dislocated my shoulder? You totally peeked at me!" Penny offered.

"True but it was only at your backside and I peeked, it was only for a second."

They both laughed but then Sheldon's face took on a serious expression. "Penny, I have to tell you something and I don't know if this is the right time to do so."

Penny sighed, "What is it Sheldon? Did Leonard and Katherine run off and get hitched?" Her voice dripped with disgust and anger.

"No not quite that extreme. But Leonard and Katherine has been pursuing a relationship and I'm afraid that she is coming over tonight for Halo night."

Penny bit down hard on her bottom lip, trying to keep her soup from coming back up. "Wow, I'm already being replaced that fast, eh?"

"Penny! Don't say that, of course you are not being replaced. Maybe by Leonard, yes but not by the rest of us and certainly not by me."

"I don't know Sheldon. She is a physicist. She's smart; I think she would fit in better with your group anyway. At least you would have more in common. I'm just a ditzy blond, I can't offer anyone anything." A part of Penny wanted to cry and feel sorry for herself but the other part was too damned tired to do so.

"Penny please do not make me angry. You know that at least to me you are a dear friend. I would never let some, some tramp take your place."

"Sheldon, I've never heard you speak like that!"

"Well I threw that in there, I thought maybe you would like it." Sheldon said through one of his breathy laughs.

"I do like it! Thank you Sheldon."

"It is no problem at all."

"No, I mean it Sheldon. Thank you."


End file.
